Loading...
1/* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
9 * These functions manipulate sctp tsn mapping array.
10 *
11 * This SCTP implementation is free software;
12 * you can redistribute it and/or modify it under the terms of
13 * the GNU General Public License as published by
14 * the Free Software Foundation; either version 2, or (at your option)
15 * any later version.
16 *
17 * This SCTP implementation is distributed in the hope that it
18 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
19 * ************************
20 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
21 * See the GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with GNU CC; see the file COPYING. If not, see
25 * <http://www.gnu.org/licenses/>.
26 *
27 * Please send any bug reports or fixes you make to the
28 * email address(es):
29 * lksctp developers <linux-sctp@vger.kernel.org>
30 *
31 * Written or modified by:
32 * La Monte H.P. Yarroll <piggy@acm.org>
33 * Jon Grimm <jgrimm@us.ibm.com>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Sridhar Samudrala <sri@us.ibm.com>
36 */
37
38#include <linux/slab.h>
39#include <linux/types.h>
40#include <linux/bitmap.h>
41#include <net/sctp/sctp.h>
42#include <net/sctp/sm.h>
43
44static void sctp_tsnmap_update(struct sctp_tsnmap *map);
45static void sctp_tsnmap_find_gap_ack(unsigned long *map, __u16 off,
46 __u16 len, __u16 *start, __u16 *end);
47static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 size);
48
49/* Initialize a block of memory as a tsnmap. */
50struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *map, __u16 len,
51 __u32 initial_tsn, gfp_t gfp)
52{
53 if (!map->tsn_map) {
54 map->tsn_map = kzalloc(len>>3, gfp);
55 if (map->tsn_map == NULL)
56 return NULL;
57
58 map->len = len;
59 } else {
60 bitmap_zero(map->tsn_map, map->len);
61 }
62
63 /* Keep track of TSNs represented by tsn_map. */
64 map->base_tsn = initial_tsn;
65 map->cumulative_tsn_ack_point = initial_tsn - 1;
66 map->max_tsn_seen = map->cumulative_tsn_ack_point;
67 map->num_dup_tsns = 0;
68
69 return map;
70}
71
72void sctp_tsnmap_free(struct sctp_tsnmap *map)
73{
74 map->len = 0;
75 kfree(map->tsn_map);
76}
77
78/* Test the tracking state of this TSN.
79 * Returns:
80 * 0 if the TSN has not yet been seen
81 * >0 if the TSN has been seen (duplicate)
82 * <0 if the TSN is invalid (too large to track)
83 */
84int sctp_tsnmap_check(const struct sctp_tsnmap *map, __u32 tsn)
85{
86 u32 gap;
87
88 /* Check to see if this is an old TSN */
89 if (TSN_lte(tsn, map->cumulative_tsn_ack_point))
90 return 1;
91
92 /* Verify that we can hold this TSN and that it will not
93 * overlfow our map
94 */
95 if (!TSN_lt(tsn, map->base_tsn + SCTP_TSN_MAP_SIZE))
96 return -1;
97
98 /* Calculate the index into the mapping arrays. */
99 gap = tsn - map->base_tsn;
100
101 /* Check to see if TSN has already been recorded. */
102 if (gap < map->len && test_bit(gap, map->tsn_map))
103 return 1;
104 else
105 return 0;
106}
107
108
109/* Mark this TSN as seen. */
110int sctp_tsnmap_mark(struct sctp_tsnmap *map, __u32 tsn,
111 struct sctp_transport *trans)
112{
113 u16 gap;
114
115 if (TSN_lt(tsn, map->base_tsn))
116 return 0;
117
118 gap = tsn - map->base_tsn;
119
120 if (gap >= map->len && !sctp_tsnmap_grow(map, gap + 1))
121 return -ENOMEM;
122
123 if (!sctp_tsnmap_has_gap(map) && gap == 0) {
124 /* In this case the map has no gaps and the tsn we are
125 * recording is the next expected tsn. We don't touch
126 * the map but simply bump the values.
127 */
128 map->max_tsn_seen++;
129 map->cumulative_tsn_ack_point++;
130 if (trans)
131 trans->sack_generation =
132 trans->asoc->peer.sack_generation;
133 map->base_tsn++;
134 } else {
135 /* Either we already have a gap, or about to record a gap, so
136 * have work to do.
137 *
138 * Bump the max.
139 */
140 if (TSN_lt(map->max_tsn_seen, tsn))
141 map->max_tsn_seen = tsn;
142
143 /* Mark the TSN as received. */
144 set_bit(gap, map->tsn_map);
145
146 /* Go fixup any internal TSN mapping variables including
147 * cumulative_tsn_ack_point.
148 */
149 sctp_tsnmap_update(map);
150 }
151
152 return 0;
153}
154
155
156/* Initialize a Gap Ack Block iterator from memory being provided. */
157static void sctp_tsnmap_iter_init(const struct sctp_tsnmap *map,
158 struct sctp_tsnmap_iter *iter)
159{
160 /* Only start looking one past the Cumulative TSN Ack Point. */
161 iter->start = map->cumulative_tsn_ack_point + 1;
162}
163
164/* Get the next Gap Ack Blocks. Returns 0 if there was not another block
165 * to get.
166 */
167static int sctp_tsnmap_next_gap_ack(const struct sctp_tsnmap *map,
168 struct sctp_tsnmap_iter *iter,
169 __u16 *start, __u16 *end)
170{
171 int ended = 0;
172 __u16 start_ = 0, end_ = 0, offset;
173
174 /* If there are no more gap acks possible, get out fast. */
175 if (TSN_lte(map->max_tsn_seen, iter->start))
176 return 0;
177
178 offset = iter->start - map->base_tsn;
179 sctp_tsnmap_find_gap_ack(map->tsn_map, offset, map->len,
180 &start_, &end_);
181
182 /* The Gap Ack Block happens to end at the end of the map. */
183 if (start_ && !end_)
184 end_ = map->len - 1;
185
186 /* If we found a Gap Ack Block, return the start and end and
187 * bump the iterator forward.
188 */
189 if (end_) {
190 /* Fix up the start and end based on the
191 * Cumulative TSN Ack which is always 1 behind base.
192 */
193 *start = start_ + 1;
194 *end = end_ + 1;
195
196 /* Move the iterator forward. */
197 iter->start = map->cumulative_tsn_ack_point + *end + 1;
198 ended = 1;
199 }
200
201 return ended;
202}
203
204/* Mark this and any lower TSN as seen. */
205void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn)
206{
207 u32 gap;
208
209 if (TSN_lt(tsn, map->base_tsn))
210 return;
211 if (!TSN_lt(tsn, map->base_tsn + SCTP_TSN_MAP_SIZE))
212 return;
213
214 /* Bump the max. */
215 if (TSN_lt(map->max_tsn_seen, tsn))
216 map->max_tsn_seen = tsn;
217
218 gap = tsn - map->base_tsn + 1;
219
220 map->base_tsn += gap;
221 map->cumulative_tsn_ack_point += gap;
222 if (gap >= map->len) {
223 /* If our gap is larger then the map size, just
224 * zero out the map.
225 */
226 bitmap_zero(map->tsn_map, map->len);
227 } else {
228 /* If the gap is smaller than the map size,
229 * shift the map by 'gap' bits and update further.
230 */
231 bitmap_shift_right(map->tsn_map, map->tsn_map, gap, map->len);
232 sctp_tsnmap_update(map);
233 }
234}
235
236/********************************************************************
237 * 2nd Level Abstractions
238 ********************************************************************/
239
240/* This private helper function updates the tsnmap buffers and
241 * the Cumulative TSN Ack Point.
242 */
243static void sctp_tsnmap_update(struct sctp_tsnmap *map)
244{
245 u16 len;
246 unsigned long zero_bit;
247
248
249 len = map->max_tsn_seen - map->cumulative_tsn_ack_point;
250 zero_bit = find_first_zero_bit(map->tsn_map, len);
251 if (!zero_bit)
252 return; /* The first 0-bit is bit 0. nothing to do */
253
254 map->base_tsn += zero_bit;
255 map->cumulative_tsn_ack_point += zero_bit;
256
257 bitmap_shift_right(map->tsn_map, map->tsn_map, zero_bit, map->len);
258}
259
260/* How many data chunks are we missing from our peer?
261 */
262__u16 sctp_tsnmap_pending(struct sctp_tsnmap *map)
263{
264 __u32 cum_tsn = map->cumulative_tsn_ack_point;
265 __u32 max_tsn = map->max_tsn_seen;
266 __u32 base_tsn = map->base_tsn;
267 __u16 pending_data;
268 u32 gap;
269
270 pending_data = max_tsn - cum_tsn;
271 gap = max_tsn - base_tsn;
272
273 if (gap == 0 || gap >= map->len)
274 goto out;
275
276 pending_data -= bitmap_weight(map->tsn_map, gap + 1);
277out:
278 return pending_data;
279}
280
281/* This is a private helper for finding Gap Ack Blocks. It searches a
282 * single array for the start and end of a Gap Ack Block.
283 *
284 * The flags "started" and "ended" tell is if we found the beginning
285 * or (respectively) the end of a Gap Ack Block.
286 */
287static void sctp_tsnmap_find_gap_ack(unsigned long *map, __u16 off,
288 __u16 len, __u16 *start, __u16 *end)
289{
290 int i = off;
291
292 /* Look through the entire array, but break out
293 * early if we have found the end of the Gap Ack Block.
294 */
295
296 /* Also, stop looking past the maximum TSN seen. */
297
298 /* Look for the start. */
299 i = find_next_bit(map, len, off);
300 if (i < len)
301 *start = i;
302
303 /* Look for the end. */
304 if (*start) {
305 /* We have found the start, let's find the
306 * end. If we find the end, break out.
307 */
308 i = find_next_zero_bit(map, len, i);
309 if (i < len)
310 *end = i - 1;
311 }
312}
313
314/* Renege that we have seen a TSN. */
315void sctp_tsnmap_renege(struct sctp_tsnmap *map, __u32 tsn)
316{
317 u32 gap;
318
319 if (TSN_lt(tsn, map->base_tsn))
320 return;
321 /* Assert: TSN is in range. */
322 if (!TSN_lt(tsn, map->base_tsn + map->len))
323 return;
324
325 gap = tsn - map->base_tsn;
326
327 /* Pretend we never saw the TSN. */
328 clear_bit(gap, map->tsn_map);
329}
330
331/* How many gap ack blocks do we have recorded? */
332__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map,
333 struct sctp_gap_ack_block *gabs)
334{
335 struct sctp_tsnmap_iter iter;
336 int ngaps = 0;
337
338 /* Refresh the gap ack information. */
339 if (sctp_tsnmap_has_gap(map)) {
340 __u16 start = 0, end = 0;
341 sctp_tsnmap_iter_init(map, &iter);
342 while (sctp_tsnmap_next_gap_ack(map, &iter,
343 &start,
344 &end)) {
345
346 gabs[ngaps].start = htons(start);
347 gabs[ngaps].end = htons(end);
348 ngaps++;
349 if (ngaps >= SCTP_MAX_GABS)
350 break;
351 }
352 }
353 return ngaps;
354}
355
356static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 size)
357{
358 unsigned long *new;
359 unsigned long inc;
360 u16 len;
361
362 if (size > SCTP_TSN_MAP_SIZE)
363 return 0;
364
365 inc = ALIGN((size - map->len), BITS_PER_LONG) + SCTP_TSN_MAP_INCREMENT;
366 len = min_t(u16, map->len + inc, SCTP_TSN_MAP_SIZE);
367
368 new = kzalloc(len>>3, GFP_ATOMIC);
369 if (!new)
370 return 0;
371
372 bitmap_copy(new, map->tsn_map,
373 map->max_tsn_seen - map->cumulative_tsn_ack_point);
374 kfree(map->tsn_map);
375 map->tsn_map = new;
376 map->len = len;
377
378 return 1;
379}
1/* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
9 * These functions manipulate sctp tsn mapping array.
10 *
11 * This SCTP implementation is free software;
12 * you can redistribute it and/or modify it under the terms of
13 * the GNU General Public License as published by
14 * the Free Software Foundation; either version 2, or (at your option)
15 * any later version.
16 *
17 * This SCTP implementation is distributed in the hope that it
18 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
19 * ************************
20 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
21 * See the GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with GNU CC; see the file COPYING. If not, write to
25 * the Free Software Foundation, 59 Temple Place - Suite 330,
26 * Boston, MA 02111-1307, USA.
27 *
28 * Please send any bug reports or fixes you make to the
29 * email address(es):
30 * lksctp developers <lksctp-developers@lists.sourceforge.net>
31 *
32 * Or submit a bug report through the following website:
33 * http://www.sf.net/projects/lksctp
34 *
35 * Written or modified by:
36 * La Monte H.P. Yarroll <piggy@acm.org>
37 * Jon Grimm <jgrimm@us.ibm.com>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Sridhar Samudrala <sri@us.ibm.com>
40 *
41 * Any bugs reported given to us we will try to fix... any fixes shared will
42 * be incorporated into the next SCTP release.
43 */
44
45#include <linux/slab.h>
46#include <linux/types.h>
47#include <linux/bitmap.h>
48#include <net/sctp/sctp.h>
49#include <net/sctp/sm.h>
50
51static void sctp_tsnmap_update(struct sctp_tsnmap *map);
52static void sctp_tsnmap_find_gap_ack(unsigned long *map, __u16 off,
53 __u16 len, __u16 *start, __u16 *end);
54static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 gap);
55
56/* Initialize a block of memory as a tsnmap. */
57struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *map, __u16 len,
58 __u32 initial_tsn, gfp_t gfp)
59{
60 if (!map->tsn_map) {
61 map->tsn_map = kzalloc(len>>3, gfp);
62 if (map->tsn_map == NULL)
63 return NULL;
64
65 map->len = len;
66 } else {
67 bitmap_zero(map->tsn_map, map->len);
68 }
69
70 /* Keep track of TSNs represented by tsn_map. */
71 map->base_tsn = initial_tsn;
72 map->cumulative_tsn_ack_point = initial_tsn - 1;
73 map->max_tsn_seen = map->cumulative_tsn_ack_point;
74 map->num_dup_tsns = 0;
75
76 return map;
77}
78
79void sctp_tsnmap_free(struct sctp_tsnmap *map)
80{
81 map->len = 0;
82 kfree(map->tsn_map);
83}
84
85/* Test the tracking state of this TSN.
86 * Returns:
87 * 0 if the TSN has not yet been seen
88 * >0 if the TSN has been seen (duplicate)
89 * <0 if the TSN is invalid (too large to track)
90 */
91int sctp_tsnmap_check(const struct sctp_tsnmap *map, __u32 tsn)
92{
93 u32 gap;
94
95 /* Check to see if this is an old TSN */
96 if (TSN_lte(tsn, map->cumulative_tsn_ack_point))
97 return 1;
98
99 /* Verify that we can hold this TSN and that it will not
100 * overlfow our map
101 */
102 if (!TSN_lt(tsn, map->base_tsn + SCTP_TSN_MAP_SIZE))
103 return -1;
104
105 /* Calculate the index into the mapping arrays. */
106 gap = tsn - map->base_tsn;
107
108 /* Check to see if TSN has already been recorded. */
109 if (gap < map->len && test_bit(gap, map->tsn_map))
110 return 1;
111 else
112 return 0;
113}
114
115
116/* Mark this TSN as seen. */
117int sctp_tsnmap_mark(struct sctp_tsnmap *map, __u32 tsn)
118{
119 u16 gap;
120
121 if (TSN_lt(tsn, map->base_tsn))
122 return 0;
123
124 gap = tsn - map->base_tsn;
125
126 if (gap >= map->len && !sctp_tsnmap_grow(map, gap))
127 return -ENOMEM;
128
129 if (!sctp_tsnmap_has_gap(map) && gap == 0) {
130 /* In this case the map has no gaps and the tsn we are
131 * recording is the next expected tsn. We don't touch
132 * the map but simply bump the values.
133 */
134 map->max_tsn_seen++;
135 map->cumulative_tsn_ack_point++;
136 map->base_tsn++;
137 } else {
138 /* Either we already have a gap, or about to record a gap, so
139 * have work to do.
140 *
141 * Bump the max.
142 */
143 if (TSN_lt(map->max_tsn_seen, tsn))
144 map->max_tsn_seen = tsn;
145
146 /* Mark the TSN as received. */
147 set_bit(gap, map->tsn_map);
148
149 /* Go fixup any internal TSN mapping variables including
150 * cumulative_tsn_ack_point.
151 */
152 sctp_tsnmap_update(map);
153 }
154
155 return 0;
156}
157
158
159/* Initialize a Gap Ack Block iterator from memory being provided. */
160SCTP_STATIC void sctp_tsnmap_iter_init(const struct sctp_tsnmap *map,
161 struct sctp_tsnmap_iter *iter)
162{
163 /* Only start looking one past the Cumulative TSN Ack Point. */
164 iter->start = map->cumulative_tsn_ack_point + 1;
165}
166
167/* Get the next Gap Ack Blocks. Returns 0 if there was not another block
168 * to get.
169 */
170SCTP_STATIC int sctp_tsnmap_next_gap_ack(const struct sctp_tsnmap *map,
171 struct sctp_tsnmap_iter *iter,
172 __u16 *start, __u16 *end)
173{
174 int ended = 0;
175 __u16 start_ = 0, end_ = 0, offset;
176
177 /* If there are no more gap acks possible, get out fast. */
178 if (TSN_lte(map->max_tsn_seen, iter->start))
179 return 0;
180
181 offset = iter->start - map->base_tsn;
182 sctp_tsnmap_find_gap_ack(map->tsn_map, offset, map->len,
183 &start_, &end_);
184
185 /* The Gap Ack Block happens to end at the end of the map. */
186 if (start_ && !end_)
187 end_ = map->len - 1;
188
189 /* If we found a Gap Ack Block, return the start and end and
190 * bump the iterator forward.
191 */
192 if (end_) {
193 /* Fix up the start and end based on the
194 * Cumulative TSN Ack which is always 1 behind base.
195 */
196 *start = start_ + 1;
197 *end = end_ + 1;
198
199 /* Move the iterator forward. */
200 iter->start = map->cumulative_tsn_ack_point + *end + 1;
201 ended = 1;
202 }
203
204 return ended;
205}
206
207/* Mark this and any lower TSN as seen. */
208void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn)
209{
210 u32 gap;
211
212 if (TSN_lt(tsn, map->base_tsn))
213 return;
214 if (!TSN_lt(tsn, map->base_tsn + SCTP_TSN_MAP_SIZE))
215 return;
216
217 /* Bump the max. */
218 if (TSN_lt(map->max_tsn_seen, tsn))
219 map->max_tsn_seen = tsn;
220
221 gap = tsn - map->base_tsn + 1;
222
223 map->base_tsn += gap;
224 map->cumulative_tsn_ack_point += gap;
225 if (gap >= map->len) {
226 /* If our gap is larger then the map size, just
227 * zero out the map.
228 */
229 bitmap_zero(map->tsn_map, map->len);
230 } else {
231 /* If the gap is smaller than the map size,
232 * shift the map by 'gap' bits and update further.
233 */
234 bitmap_shift_right(map->tsn_map, map->tsn_map, gap, map->len);
235 sctp_tsnmap_update(map);
236 }
237}
238
239/********************************************************************
240 * 2nd Level Abstractions
241 ********************************************************************/
242
243/* This private helper function updates the tsnmap buffers and
244 * the Cumulative TSN Ack Point.
245 */
246static void sctp_tsnmap_update(struct sctp_tsnmap *map)
247{
248 u16 len;
249 unsigned long zero_bit;
250
251
252 len = map->max_tsn_seen - map->cumulative_tsn_ack_point;
253 zero_bit = find_first_zero_bit(map->tsn_map, len);
254 if (!zero_bit)
255 return; /* The first 0-bit is bit 0. nothing to do */
256
257 map->base_tsn += zero_bit;
258 map->cumulative_tsn_ack_point += zero_bit;
259
260 bitmap_shift_right(map->tsn_map, map->tsn_map, zero_bit, map->len);
261}
262
263/* How many data chunks are we missing from our peer?
264 */
265__u16 sctp_tsnmap_pending(struct sctp_tsnmap *map)
266{
267 __u32 cum_tsn = map->cumulative_tsn_ack_point;
268 __u32 max_tsn = map->max_tsn_seen;
269 __u32 base_tsn = map->base_tsn;
270 __u16 pending_data;
271 u32 gap, i;
272
273 pending_data = max_tsn - cum_tsn;
274 gap = max_tsn - base_tsn;
275
276 if (gap == 0 || gap >= map->len)
277 goto out;
278
279 for (i = 0; i < gap+1; i++) {
280 if (test_bit(i, map->tsn_map))
281 pending_data--;
282 }
283
284out:
285 return pending_data;
286}
287
288/* This is a private helper for finding Gap Ack Blocks. It searches a
289 * single array for the start and end of a Gap Ack Block.
290 *
291 * The flags "started" and "ended" tell is if we found the beginning
292 * or (respectively) the end of a Gap Ack Block.
293 */
294static void sctp_tsnmap_find_gap_ack(unsigned long *map, __u16 off,
295 __u16 len, __u16 *start, __u16 *end)
296{
297 int i = off;
298
299 /* Look through the entire array, but break out
300 * early if we have found the end of the Gap Ack Block.
301 */
302
303 /* Also, stop looking past the maximum TSN seen. */
304
305 /* Look for the start. */
306 i = find_next_bit(map, len, off);
307 if (i < len)
308 *start = i;
309
310 /* Look for the end. */
311 if (*start) {
312 /* We have found the start, let's find the
313 * end. If we find the end, break out.
314 */
315 i = find_next_zero_bit(map, len, i);
316 if (i < len)
317 *end = i - 1;
318 }
319}
320
321/* Renege that we have seen a TSN. */
322void sctp_tsnmap_renege(struct sctp_tsnmap *map, __u32 tsn)
323{
324 u32 gap;
325
326 if (TSN_lt(tsn, map->base_tsn))
327 return;
328 /* Assert: TSN is in range. */
329 if (!TSN_lt(tsn, map->base_tsn + map->len))
330 return;
331
332 gap = tsn - map->base_tsn;
333
334 /* Pretend we never saw the TSN. */
335 clear_bit(gap, map->tsn_map);
336}
337
338/* How many gap ack blocks do we have recorded? */
339__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map,
340 struct sctp_gap_ack_block *gabs)
341{
342 struct sctp_tsnmap_iter iter;
343 int ngaps = 0;
344
345 /* Refresh the gap ack information. */
346 if (sctp_tsnmap_has_gap(map)) {
347 __u16 start = 0, end = 0;
348 sctp_tsnmap_iter_init(map, &iter);
349 while (sctp_tsnmap_next_gap_ack(map, &iter,
350 &start,
351 &end)) {
352
353 gabs[ngaps].start = htons(start);
354 gabs[ngaps].end = htons(end);
355 ngaps++;
356 if (ngaps >= SCTP_MAX_GABS)
357 break;
358 }
359 }
360 return ngaps;
361}
362
363static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 gap)
364{
365 unsigned long *new;
366 unsigned long inc;
367 u16 len;
368
369 if (gap >= SCTP_TSN_MAP_SIZE)
370 return 0;
371
372 inc = ALIGN((gap - map->len),BITS_PER_LONG) + SCTP_TSN_MAP_INCREMENT;
373 len = min_t(u16, map->len + inc, SCTP_TSN_MAP_SIZE);
374
375 new = kzalloc(len>>3, GFP_ATOMIC);
376 if (!new)
377 return 0;
378
379 bitmap_copy(new, map->tsn_map, map->max_tsn_seen - map->base_tsn);
380 kfree(map->tsn_map);
381 map->tsn_map = new;
382 map->len = len;
383
384 return 1;
385}